Tire building apparatus of the type to which the present invention pertains conventionally comprises an intermediate radially expandable drum about which tire material is adapted to be arranged in substantially cylindrical form. Tire bead locating and supporting means are arranged axially outwardly of the intermediate drum, and are operative to lock the tire material with adjacently located tire beads. Thereafter, the intermediate drum is expanded radially, while the locked tire beads are moved axially inwardly.
With known tire building apparatus of the type indicated above, and because of the nature of the operating mechanism thereof, it has been difficult to obtain an accurate bead lock, an accurate bead set dimension, accurate control of the movement of the beads during expansion of the tire building drum, and ultimately a precisely symmetrical tire.